Patent GB-727233-A (GB)
Title: Improvements in or relating to an internal combustion engine and method of operatingthe same
IPC: F01B9/04
Filed: 1950-10-20
Abstract: 727,233. Two-stroke engines ; cylinders ; fuel injectors valves ; cooling. RESEARCH ENGINEERING CORPORATION. Oct. 20, 1950 [Jan. 18, 1950], No. 25604/50. Classes 7(2), 7(3) and 7(6). A two-stroke diesel engine has a cylinder 20, Fig. 7, in-phase opposed pistons 22, 23 therein with individual crankshafts 35 interconnected for common rotation, fuel injection means located approximately in the central transverse plane of the cylinder, to which plane piston-controlled exhaust ports 80 are closer than piston-controlled intake, e.g. scavenge-air, ports 60 so as to open before the ports 60, and exhaust control means such as a rotary valve 89 for effectively closing the ports 80 ahead of the ports 60 to allow supercharging. As applied to a marine engine, pistons 22, 23 are provided in each of two side-by-side cylinders 20 and drive an output shaft 47 through crankshafts 35 and spiral bevel gears 42, 50 and 46, 51, the gear 50 being slidingly splined to the shaft 47 to allow for thermal expansion thereof. Further bevel gears (not shown) meshing the gear 51 provide drives for fuel injection and lubricating oil pumps (not shown), whilst a gear 52 powers a scavenging air blower 134, Fig. 2 (side view of the engine), delivering to the ports 60 via a filter 136 and an aluminium intake casing 62, Fig. 7. An instrument and control panel 140 is provided. V-belt pulleys 122 on the shaft 47 power a generator (not shown) and other accessories as desired. Cylinder ports. The ports 80 are angled, as shown in Fig. 10, and the ports 60 are similarly but oppositely directed so that the scavenging and charging air passes along the cylinder in a continuous spiral. Fuel injectors. An injection nozzle 124, Fig. 12, situated centrally of each cylinder directs fuel non-radially into the air stream, the nozzle being mounted on a collar 120 on the liner 24. Exhaust valves and passages. The rotary valve 89 comprises a preferably cast-iron hub slidably splined on the shaft 47 and situated at the exits of spiral exhaust passages 85, Fig. 10, to monitor the discharge from the ports 80 through them to an outlet 97 connected to a silencer or atmosphere. Cooling charge, cylinders and exhaust. The passages 85 form the inner skin of a double walled aluminium casing 83 within which fresh water is circulated to cool the passages. Each cylinder 20 consists of a liner 24, Fig. 7, spaced from a water jacket 25 by annular collars 26, 27, 29, 30. The casings 83, 62 are floatingly mounted on the jacket 25 with the interposition of sealing rings, of neoprene for the casing 62. Fresh water supplied, as described below, to an inlet 67, Fig. 9, of a cooling chamber 66 occupying the left hand side (in Fig. 7) of the lower half of the casing 62 passes from the chamber 66 through openings 68 into the jacket 25 and circulates therethrough by means of axial passages (as 82, Fig. 10) through the collars 26, 27, before entering the casing 83 through openings 106, Fig. 13, located on either side of the passages 85. From the casing 83 the water passes back to the inlet 67, either directly via a pipe 117, Fig. 10, or, if a thermostat 115 has opened a pipe 116 on the engine becoming warm, via the main cooling system, consisting of a fresh water pump 128, Fig. 2, a heat exchanger 127 and an expansion tank leading back to the inlet 67. A pump (not shown) delivers seawater to the heat exchanger 127 for cooling thereof. Sealing rings 119, having bronze bearing surfaces backed by a resilient material such as impregnated felt seating in grooves 118, are provided between the casing 83 and shaft 47.